Adjustment of planned movement based on radio network conditions

ABSTRACT

A movement adjusting device adjusts the movement of a wireless transceiver moving according to a plan along a route through a wireless communication network ( 10, 12 ) while communicating for an application having a service requirement on the wireless communication network ( 10, 12 ), the wireless communication network ( 10, 12 ) comprises cells ( 14, 16, 18, 20 ) and the movement adjusting device is operative to: obtain radio network condition data (RSRP, RSRQ) regarding a group of cells ( 14, 16, 18, 20 ) comprising a current cell ( 14 ) in which the wireless transceiver ( 28 ) is located and a number of neighboring cells ( 16, 18, 20 ) into which the wireless transceiver ( 28 ) may move, analyze the radio network condition data (RSRQ, RSRP) with regard to fulfilling the service requirement of the application ( 26 ), and make an adjustment of the planned movement if the analysis indicates that this would improve on the fulfilling of the service requirement.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a 35 U.S.C. § 371 National Phase Entry Applicationfrom PCT/SE2015/051335, filed Dec. 14, 2015, designating the UnitedStates, the disclosure of which is incorporated by reference.

TECHNICAL FIELD

The invention relates to a wireless terminal travelling through awireless communication system. More particularly, the invention relatesto a movement adjustment device, method, computer program and computerprogram product for adjusting a movement of a wireless transceivermoving according to a plan along a route through a wirelesscommunication network.

BACKGROUND

Unmanned vessels, such as vehicles like cars and trucks, and aerial oneslike drones, are dependent on connectivity primarily for monitoring andcontrol. A type of unmanned aerial vehicle, autonomous vehicles movingover large distances are, even if they manage basic mobility, dependenton cellular access for security, remote control purposes and tocontinuously transfer recorded data, e.g. locations, status of engineand/or battery, images or video, to some central location.

One particularly interesting group of such vehicles is the UnmannedAerial Vehicle (UAV). There is a growing interest for UAVs like fromhigh-profile business cases—such as for delivery of consumer products,such as books, gadgets and soft drinks and even hot food like pizza.However, there are also everyday use cases that extend from filmmakingand aerial photography to fields such as real estate, farming andpipeline maintenance. Journalists want to work with them. As dometeorologists. Also, consumers may use UAVs to take amazing vacationpictures.

State of the art manually operated drones like Parrot Bebop or PhantomDji 2 Vision have a range of 400 m to 2 km (Open Area). This makes itimpossible for one operator to remotely control more than one drone atthe time and the range is limited to the range of the radio transmitter.

Multiple drones moving over larger areas with the purpose of deliveryservices will be dependent on wide area radio access for security,safety and remote operation purposes. The drone will thus carry awireless transceiver that is carried through the coverage area of awireless communication network.

Such moving wireless transceivers that provide services live video andmetadata, to for instance a remote operations centre, for theapplications related to agriculture, public safety, oil and gasexploration, etc., may put high requirements on the radio networkperformance of the wireless communication network.

In a scenario where a moving wireless transceiver passes through a cellof the wireless communication network during which it transmits, e.g.high definition real time video, the wireless transceiver will putsignificant load onto the cell at question. If the cell already beforeentrance of the wireless transceiver is highly loaded, both radionetwork key performance indexes (KPIs) and a video quality measure ofthe video will suffer.

In a further scenario where a multitude of moving wireless transceiverssupplying high-definition-video frequently pass through a cell, thatcontent traffic itself can deplete a large portion of the cellularcapacity in a given area.

It would therefore be suitable if a vessel carrying a wirelesstransceiver could adapt its mission path with respect not only to thefulfilling of the service KPI, but also to avoid burdening a part of thewireless communication network already having a high load.

SUMMARY

The invention is therefore directed towards improving on the fulfillingof a service requirement while at the same time avoiding placing anundue burden on the wireless communication network.

This object is according to a first aspect achieved by a movementadjustment device for adjusting a movement of a wireless transceiver.The transceiver is moving according to a plan along a route through awireless communication network while at the same time communicating foran application having a service requirement on the wirelesscommunication network. The wireless communication network in turncomprises cells. The movement adjusting device comprises a processoracting on computer instructions whereby the movement adjusting device isconfigured to:

obtain radio network condition data regarding a group of cells, wherethis group comprises a current cell in which the wireless transceiver islocated and a number of neighbouring cells into which the wirelesstransceiver may move,

analyse the radio network condition data with regard to fulfilling theservice requirement of the application, and

make an adjustment of the planned movement if the analysis indicatesthat this would improve on the fulfilling of the service requirement.

The object is according to a second aspect achieved through a method ofadjusting the movement of a wireless transceiver. The transceiver ismoving according to a plan along a route through a wirelesscommunication network while at the same time communicating for anapplication having a service requirement on the wireless communicationnetwork. The wireless communication network comprises cells and themethod is performed in a movement adjusting device. The methodcomprises:

obtaining radio network condition data regarding a group of cells, wherethis group comprises a current cell in which the wireless transceiver islocated and a number of neighbouring cells into which the wirelesstransceiver may move,

analysing the radio network condition data with regard to fulfilling theservice requirement of the application, and

making an adjustment of the planned movement if the analysis indicatesthat this would improve on the fulfilling of the service requirement

The object is according to a third aspect achieved through a movementadjustment device for adjusting a movement of a wireless transceiver.The transceiver is moving according to a plan along a route through awireless communication network while at the same time communicating foran application having a service requirement on the wirelesscommunication network. The wireless communication network in turncomprises cells. The movement adjusting device comprises:

means for obtaining radio network condition data regarding a group ofcells comprising a current cell in which the wireless transceiver islocated and a number of neighbouring cells into which the wirelesstransceiver may move,

means for analysing the radio network condition data with regard tofulfilling the service requirement of the application, and

means for making an adjustment of the planned movement if the analysisindicates that this would improve on the fulfilling of the servicerequirement.

The object is according to a fourth aspect achieved through a computerprogram for adjusting a movement of a wireless transceiver. Thetransceiver is moving according to a plan along a route through awireless communication network while at the same time communicating foran application having a service requirement on the wirelesscommunication network. The wireless communication network in turncomprises cells. The computer program comprises computer program codewhich when run in a movement adjusting device, causes the movementadjusting device to:

obtain radio network condition data regarding a group of cellscomprising a current cell in which the wireless transceiver is locatedand a number of neighbouring cells into which the wireless transceivermay move,

analyse the radio network condition data with regard to fulfilling theservice requirement of the application, and

make an adjustment of the planned movement if the analysis indicatesthat this would improve on the fulfilling of the service requirement.

The object is according to a fifth aspect achieved through a computerprogram product for adjusting a movement of a wireless transceivermoving according to a plan along a route through a wirelesscommunication network. The computer program comprises a data medium withcomputer program code according to the fourth aspect.

The radio network condition data may comprise cell load data for atleast the neighbouring cells

In a first variation of the first aspect, when analysing the radionetwork condition data the movement adjustment device may in this casebe configured to is operative to evaluate the cell loads defined in thecell load data with regard to fulfilling the service requirement andwhen adjusting planned movement is configured to adjust the plannedmovement so that the cell load along the route after the current cell islower after the adjustment than before the adjustment.

In a corresponding variation of the second aspect the analysing of theradio network condition data may comprise evaluating the cell loadsdefined in the cell load data with regard to fulfilling the servicerequirement and the making of an adjustment of planned movementcomprises adjusting the planned movement so that the cell load along theroute after the current cell is lower after the adjustment than beforethe adjustment.

The radio network condition data may comprise data concerning radio linkquality between the cells and the wireless transceiver.

In a second variation of the first aspect, the movement adjusting deviceis, when obtaining radio network condition data, further configured todetermine cell load estimates for the neighbouring cells based on theradio link quality data and a cell geometry measure, where the cellgeometry measure of a cell is based on a signal strength of the cell asdetected by the wireless transceiver divided by corresponding signalstrengths of the other cells of the group and the cell load estimatesare provided as the cell load data.

In a corresponding variation of the second aspect, the obtaining ofradio network condition data comprises determining cell load estimatesfor the neighbouring cells based on the radio link quality data and acell geometry measure, where the cell geometry measure of a cell isbased on a signal strength of the cell as detected by the wirelesstransceiver divided by corresponding signal strengths of the other cellsof the group and the cell load estimates being provided as the cell loaddata.

In a third variation of the first aspect, the movement adjusting deviceis further configured to, when obtaining radio network condition data,estimate the loads of the neighbouring cells based on responses torequests for resources sent from the wireless transceiver to theneighbouring cells and provide the load estimations as the cell loaddata.

In a corresponding variation of the second aspect, the obtaining ofradio network condition data comprises estimating the loads of theneighbouring cells based on responses to requests for resources sentfrom the wireless transceiver to the neighbouring cells and providingthe load estimations as the cell load data.

In a fourth variation of the first and second aspect, the adjustment ofthe planned movement is a change of the cells that the route passes. Thechange of cells may comprise a change in a vertical direction.

In a fifth variation of the first and second aspects the adjustment ofplanned movement is based on mission constraints of a mission in whichthe application is operated.

In a sixth variation of the first and second aspects the radio networkcondition data comprises statistical cell load data.

In a seventh variation of the first aspect, the movement adjustmentdevice, when making an adjustment of the planned movement is furtherconfigured to adjust the speed with which the wireless transceiver movesfor changing the time at which a cell is passed in the route.

In a corresponding variation of the second aspect, the making of anadjustment of the planned movement comprises adjusting the speed withwhich the wireless transceiver moves for changing the time at which acell is passed in the route.

In an eighth variation of the first aspect, the movement adjustmentdevice is further configured to change the service requirement if itcannot be fulfilled with any movement, changed or unchanged.

In a corresponding variation of the second aspect, the method furthercomprises changing the service requirement if it cannot be fulfilledwith any movement, changed or unchanged.

The movement adjustment may be physically placed in different locations.It may be provided in a vessel such as an Unmanned Aerial Vehicle (UAV).Alternatively it may be provided as a remote operations centre. However,it may just as well be provided in a completely different environment,such as in a cloud computing environment with which a vessel or a remoteoperations centre communicates.

The invention has a number of advantages. It allows adjustment of aplanned movement of a wireless transceiver so that the servicerequirement of the associated application is fulfilled. Thereby it ispossible to obtain an optimized operation based on network conditions.At the same time a cell that experiences an already heavy load may berelieved of having the load increased, which may be beneficial for thewireless network operator.

It should be emphasized that the term “comprises/comprising” when usedin this specification is taken to specify the presence of statedfeatures, integers, steps or components, but does not preclude thepresence or addition of one or more other features, integers, steps,components or groups thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail in relation to theenclosed drawings, in which:

FIG. 1 schematically shows a remote operations centre connected to awireless communication network comprising base stations in cells as wellas a vessel that communicates with the base stations,

FIG. 2 shows a block schematic of some of the content of the vesselcomprising an application, a wireless transceiver and a movementadjusting device,

FIG. 3 shows a block schematic of a first realization of the movementadjusting device,

FIG. 4 shows a block schematic of a second realization of the movementadjusting device,

FIG. 5 shows a flow chart of a number of steps being performed in afirst embodiment of a method for adjusting the movement of the wirelesstransceiver,

FIG. 6 shows a flow chart of a number of steps being performed in asecond embodiment of the method for adjusting the movement of thewireless transceiver,

FIG. 7 schematically shows an originally planned route through thewireless communication network,

FIG. 8 schematically shows the originally planned route together withtwo proposed route adjustments, and

FIG. 9 shows a computer program product comprising a data carrier withcomputer program code for implementing functionality of the movementadjusting device.

DETAILED DESCRIPTION

In the following description, for purposes of explanation and notlimitation, specific details are set forth such as particulararchitectures, interfaces, techniques, etc. in order to provide athorough understanding of the invention. However, it will be apparent tothose skilled in the art that the invention may be practiced in otherembodiments that depart from these specific details. In other instances,detailed descriptions of well-known devices, circuits, and methods areomitted so as not to obscure the description of the invention withunnecessary detail.

The present invention concerns the adjustment of a planned route or pathfor a wireless transceiver travelling through a wireless communicationnetwork, where the wireless transceiver may be provided in a vessel,such as an unmanned aerial vehicle (UAV) and set to communicate for anapplication having a service requirement on the wireless communicationnetwork. The application may for instance be a high-definition videocapturing application that transmits high-definition video to areceiving entity via the wireless communication network. The bandwidthrequirement of such an application may be high on the wirelesscommunication network.

The wireless communication network may as an example be a mobilecommunication network like a Long-Term Evolution (LTE), Universal MobileTelecommunications System (UMTS) and Global System for MobileCommunications (GSM). The invention will be described below in relationto LTE. However, since most wireless terminals today support severalradio access technologies (RAT), the invention may use any of theexisting RATs, such as UMTS, GSM, or CDMA2000, where CDMA is an acronymfor Code Division Multiple Access. These are just a few examples ofnetworks where the invention may be used. Another type of network wherethe invention may be used is a Wireless Local Area Network (WLAN) usingthe Institute of Electrical and Electronics Engineers (IEEE) 802.11standard.

FIG. 1 schematically shows a wireless communication network which may bea network according to any of the above described types. The network mayfurthermore comprise an access network AN 10 and a core network CN 12,where the access network 10 comprises a first base station 13 providingcoverage of a first cell C114, a second base station 15 providingcoverage of a second cell C2 16, a third base station 17 providingcoverage of a third cell C3 18 and a fourth base station 19 providingcoverage of a fourth cell C4 20. It should here be realized that a basestation may provide more than one cell.

In FIG. 1 there is also shown a vessel in the exemplifying form of anUnmanned Aerial Vehicle (UAV) 24. The UAV 24 is indicated as beinglocated within the first cell C1 and set to move into the fourth cellC4, where the first cell 14 is a current cell and the fourth cell 20 anext cell according to a planned route. Furthermore, it can be seen thatthe UAV 24 is exchanging radio network condition data with all of thebase stations, where the radio network condition data shown in FIG. 1 isin the form of radio link quality measures exemplified by ReferenceSignal Received Power (RSRP) and Reference Signal Received Quality(RSRQ).

Finally it can be seen that there is a remote operations centre 22connected to the core network 12. As will become apparent later on theUAV 24 comprises a wireless transceiver that may be communicating withthe remote operations centre 22 in relation to an application that isoperating in the UAV 24. For this reason, the remote operations centre22 may be responsible for assigning UAVs to various assignments, forpre-flight route planning and management & operation of UAVs in adedicated control area, where a dedicated control area may be a physicalarea covered by at least a part of the wireless communication network.

FIG. 2 shows a block schematic of some of the content of the UAV 24. TheUAV 24 comprises a wireless transceiver TR 28 set to communicateaccording to the wireless communication standard employed by thewireless communication network, which in this case is LTE. It alsocomprises an application APP 26 that provides and/or receives data fromthe wireless communication network via the wireless transceiver 28. Oneexample of such data is high-definition video. Other examples of dataare still images, UAV position and status data. Therefore theapplication 26 is connected to the wireless transceiver 28. There isalso a movement adjusting device MAD 32 that may adjust the movement ofthe UAV 24 as well as an UAV controller UAV CTRL 30, which performscontrol of the UAV 24, such as control of in which direction it is tomove, both vertically and horizontally as well the speed with which itis to move. For this reason the UAV controller 30 is typically connectedto the throttle of an engine or to a motor of the UAV as well as tovarious guiding and braking elements such as flaps and brakes. Themovement adjusting device 32 is provided for adjusting a plannedmovement of the UAV 24 based on service requirements of the application26 on the wireless communication network and radio network conditiondata of the wireless network. For this reason the movement adjustingdevice 32 is connected to the application 26, to the wirelesstransceiver 28 and to the UAV controller 30.

FIG. 3 shows a block schematic of a first way of realizing the movementadjusting device 32. It may be provided in the form of a processor PR 34connected to a program memory M 36. The program memory 36 may comprise anumber of computer instructions implementing the functionality of themovement adjusting device 32 and the processor 34 implements thisfunctionality when acting on these instructions. It can thus be seenthat the combination of processor 34 and memory 36 provides the movementadjusting device 32.

FIG. 4 shows a block schematic of a second way of realizing the movementadjusting device 32. The movement adjusting device 32 may comprise anetwork condition data obtainer NCDO 38, a network condition dataanalyser NCDA 40 and a planned movement adjuster PMA 42.

The elements in FIG. 4 may be provided as software blocks for instanceas software blocks in a program memory, but also as a part of dedicatedspecial purpose circuits, such as Application Specific IntegratedCircuits (ASICs) and Field-Programmable Gate Arrays (FPGAs). It is alsopossible to combine more than one element or block in such a circuit.

As mentioned above, the UAV 24 may provide a service in relation to anapplication 26, which application may need to utilize the wirelesscommunication network. In this the UAV 24 may furthermore travel along aplanned route, i.e. a route that has been planned for the UAV. Acommunication network is not static, it is dynamic in that the abilityto provide the service may vary from cell to cell and also from time totime for a cell. The ability of the network to fulfil the servicerequirement may thus vary and this means that if nothing is done thenthe application may not be able to perform as required. Furthermore, incase the application is traffic intensive and uses a cell having a highload, the ability of the cell to serve other users may also be degraded.Aspects of the invention are directed towards addressing these issues.

A first embodiment will now be described with reference being made alsoto FIG. 5, which shows a flow chart of method steps being performed in amethod of adjusting the movement of the wireless transceiver 28according to a plan along a route through the wireless communicationnetwork, where the method steps are being performed by the movementadjusting device 32. Furthermore, the wireless transceiver 28communicates for the application 26, which in turn has a servicerequirement on the wireless communication network. The operation of theapplication is also performed in a mission carried out by the UAV 24.

The UAV 24 may be travelling through the wireless communication networkaccording to a plan, which plan may set out a route according to whichit will pass various geographical locations as well as when it is topass these locations. This route will thereby also define what cells ofthe wireless communication network the UAV is to pass as well as when itis to pass through them. The route may furthermore be pre-determined bythe remote operations centre 22. During this time the network conditiondata obtainer 38 may obtain radio network condition data from thewireless communication network, such as from the cells of the wirelesscommunication network, which data may comprise the above mentioned RSRPand RSRQ, which are examples of radio link quality data. However, alsoother data may be obtained such as physical resource block (PRB)allocations and signal to noise ratio (SINR) may be obtained from thecells. This data may be obtained continuously. However, it is as analternative possible that the data is obtained and used at specificinstances, such as if the UAV is close to a cell border, i.e. as it isclose to entering the coverage area of a new cell.

The UAV may, in the example of FIG. 1, be in the coverage area of thefirst current cell 14 and move according to the planned route towardsthe fourth cell 20. When it does this the network condition dataobtainer 38 may obtain radio network condition data from all the cellsin its vicinity. It may thus obtain data that is indicative of the radioconditions of a cell, such as if a cell is congested or has a high load.The network condition data obtainer 38 thus obtains radio networkcondition data regarding a group of cells comprising a current cell inwhich the wireless transceiver 28 is located and a number ofneighbouring cells 16, 18, 20 into which the wireless transceiver 28 maymove from the current cell, step 44. In the example of FIG. 1, the radionetwork condition data obtainer 38 obtains data from the first, second,third and fourth cells 14, 16, 18 and 20, where this data is collectedby the wireless transceiver 28. The wireless transceiver 28 may forinstance collect this type of data as a part of investigating handoverfrom the first cell 14 to any of the second, third and fourth cells 16,18 and 20 and transfer it to the network condition data obtainer 38. Theradio network condition data obtained in this way by the networkcondition data obtainer 38 may for instance comprise radio link qualitydata such as RSRP and RSRQ. The obtaining of radio network conditiondata performed by the network condition data obtainer 38 may alsoinvolve determining estimated cell loads based on collected radio linkquality data.

The estimating of the load of the cells may involve estimation both ofthe load of the current cell as well as the load of the cells into whichthe UAV may be travelling, both according to the predetermined route aswell as the cells that may be alternatives. The radio network conditiondata may thus comprise cell load data for at least the neighbour cells,i.e. the neighbours of the current cell. The cell loads may as anexample be estimated using radio link quality data and a cell geometrymeasure. Alternatively the cell load may be determined based on arequest for resources sent from the wireless transceiver 28 to a basestation and received response to the request with the actual resourceallocation, for instance physical resource block (PRB) allocations givenby the cell. If for instance the request for resources is a request fora high bandwidth, such as a request for a maximum allowed bandwidth, andthe granted bandwidth is low, then the cell load may be estimated to behigh. After having obtained the estimated cell loads, the networkcondition data obtainer 38 then forwards the obtained radio networkcondition data to the network condition data analyser 40.

The network condition data analyser 40 analyses the radio networkcondition data with regard to fulfilling the service requirement of theapplication 26 on the communication network, step 46. The servicerequirement, here also denoted key performance indicator (KPI), whichmay set out a desired minimum delay, a required bandwidth or some othertype of requirement on the wireless communication network, may be staticand known in advance. This may be the case if for instance theapplication always has the same requirement. In other cases therequirement may be unknown or it may be dynamic, i.e. vary with time. Ifthe requirement is known and static the network condition data analyser40 may have knowledge of the requirement and may therefore not need tocontact the application 26. However, if it is not unknown or dynamic,the network condition data analyser 40 may connect to the application 26in order to get information about the KPI, which may thus be an unknownstatic value, a dynamic value or semi-dynamic value.

The analysis may involve evaluating if and in what degree the cells maysucceed in fulfilling the service requirement based on the estimatedcell loads. It may evaluate the cell loads defined in the cell load datawith regards to fulfilling service requirement.

Typically, the higher the cell load is, the lower the probability of thewireless communication network being able to fulfil the servicerequirement is.

After having analysed the radio network condition data with regard tofulfilling the service requirement, which may be done throughcorrelating the estimated cell loads with the service requirement, thenetwork condition data analyser 40 forwards, to the planned movementadjuster 42, a prediction of if and perhaps to what degree the cells,i.e. the cell in the path and the possible alternatives, are able tofulfil the service requirement.

The planned movement adjuster 42 receives these predictions and thenadjusts the planned movement so that the estimated cell load along theroute after the current cell is lower after the adjustment than beforethe adjustment, if this is deemed to improve on the fulfillment of theservice requirement, step 48. This means that if the next cell in theplanned route fulfils the service requirement, then the planned movementof the UAV may remain unchanged. However, if it is unable to fulfil theservice requirement, then a change in the movement is made. The changemay be a change in the speed of the movement or a change in thedirection of the movement. It may also be both a change of speed anddirection. In order to make these changes it is possible that theplanned movement adjuster 42 instructs the UAV controller 30 to make aspeed and or direction change, where a change of direction may involve achange to a new next cell. A change of cell may involve a change to acell that has a lower load than the originally planned next cell andwith advantage a cell of the investigated alternatives having the lowestload. Alternatively it may be a selection of cell that has asufficiently low load for the service requirement to be fulfilled thatat the same time involves the smallest change of the planned route. Achange of speed may involve a change of speed so that the UAV reachesand passes a cell along the route at a time when this cell is believedto have a load that will allow the cell to fulfil the servicerequirement. A change of direction may be a change in the horizontaldirection, the vertical direction or in both the horizontal and verticaldirections.

It can in this way be seen that it is possible to adjust the plannedmovement of the UAV 24 so that the service requirement is fulfilled.Thereby it is possible to obtain an optimized operation of a UAV basedon network conditions. By taking network load and utilization intoconsideration, the UAV will achieve better prerequisites to maintain itsmission KPIs. At the same time a cell that experiences an already heavyload may be relieved of having the load increased, which may bebeneficial for the wireless network operator.

It can also be seen that it is possible to optimize operation of UAVsbased on collection and analysis of network data such as RSRP, RSRQ andphysical resource block (PRB) allocation as well as entities derivedfrom such network data, like geometry, scheduling fraction, etc.

Now a second embodiment will be described with reference being made toFIG. 6, which shows a flow chart of a number of method steps beingperformed in the method for adjusting the movement of the wirelesstransceiver 28 according to a plan along a route and also beingperformed by the movement adjusting device 32.

The UAV 24 may yet again be travelling through the wirelesscommunication network according to a plan setting out a route accordingto which it will pass cells of the wireless communication network andmay again be located in the first cell 14, which is thereby a currentcell. The application 26 may again have a requirement on the wirelesscommunication network, which as an example may be a certain bandwidthfor high-definition video. During this time the network condition dataobtainer 38 may obtain some radio network condition data from thewireless transceiver 28 in the form of radio link quality measures fromthe cells, step 50. These radio link quality measures are received bothfrom the current cell 14 as well as from the neighbouring cells 16, 18,20 into which the wireless transceiver 28 may be transported by the UA424, where the fourth cell 20 is yet again the next cell it will enterinto according to the planned route. The radio link quality measurescollected by the wireless transceiver 28 may for instance comprise theabove mentioned RSRP and RSRQ as well as a radio link quality value,such as Signal-to-Interference and Noise Ratio (SINR). This data mayalso here be collected as a part of investigating possible handoversfrom the first cell 18 to any of the second, third and fourth cells 16,18 and 20. Some of these values may more particularly relate to a pilotsignal transmitted by the prospective destination cells. The wirelesstransceiver may thus detect signal strengths such as RSRP, RSRQ as wellas SINR of the cells 16, 18 and 20. It is also possible that these aremeasured for a pilot signal also in the current cell 144. However, asthe wireless transceiver 28 is communicating via the current cell 14, anumber of other signals may be used for the same purposes with regard tothis current cell.

The radio link quality measures are thus obtained by the networkcondition data obtainer 38 from the first, second, third and fourthcells 14, 16, 18 and 20, where this data was collected by the wirelesstransceiver 28 and transferred to the radio network condition dataobtainer 38. In addition to this, the network condition data obtainer 38also obtains a geometry measure of each of the cells, step 52.

A geometry measure of a cell may be based on a signal strength of thecell as detected by the wireless transceiver 28 divided by the sum ofcorresponding signal strengths of the other cells of the group. Ageography measure may as an example be based on the RSRP of the celldivided by the sum of RSRPs of the other cells. The geometry measure ofthe fourth cell may thus be determined as the RSRP of the fourth cell 20divided by the sum of RSRPs of the first, second and third cells 14, 16and 18. In this way a geometry measure may be determined for all of thepossible candidate cells 16, 18 and 20 that the wireless transceiver 28may enter. It is possible, but not required that a geometry measure isdetermined also for the current cell 14. More information about howgeometry measures may be obtained can be found in WO2012/118414, whichis herein incorporated by reference.

The various values are in many cases expressed in dB. In this case it ispossible that some of the operations can be performed in the logarithmicdomain. However, in order to perform the summation it may be necessaryto transform the dB values to the corresponding real values. This meansthat the individual RSRP values in dB would have to be raised using abase of 10 if they are in dB. The sum of the individual RSRP values maytherefore be obtained through 10^(RSRP2/10)+10^(RSRP3/10)+10^(RSRP4/10).This may then be transformed back to a dB value which may subtractedfrom the dB value RSRP1 of the cell investigated in order to perform thedivision. Alternatively it is possible that the division is done usingreal values. The transformation of logarithmic values to real values andvice versa, is well known in the art and therefore a detaileddescription f these aspects have been omitted.

The network data obtainer 38 may furthermore also estimate the cellloads based on the radio link quality data and the cell geometrymeasure, step 54. A cell load may more particularly be determined as thecell geometry measure of a cell divided by the radio link quality valueSINR of the same cell. In this way the load may be estimated for all thecells that are neighbours to the current cell, or perhaps only theneighbour cells that are possible to enter given the direction of travelof the wireless transceiver 28.

The cell load estimates are then provided as cell load data from thenetwork condition data obtainer 38 to the network condition dataanalyser 40.

The network condition data analyser 40 will then analyse the radionetwork condition data with regard to fulfilling the service requirementor KPI of the application 26. In order to do this the network conditiondata analyser 40 may connect to the application 26 and be informed aboutthe KPI, which as was stated above may be a required bandwidth, andthereby the network condition data analyser 40 obtains the KPI, step 56.Alternatively it may know of the KPI in advance. It may in this case beobtained from an internal memory. Thereafter the network condition dataanalyser 40 evaluates the cell load of the following or next cell in theplanned route with regard to the KPI, step 58. In the present example itthus investigates the fourth cell 20. It may furthermore make the sametype of evaluation for all the candidate cells. However, it is possiblethat such further evaluations are only made if the new cell 20 accordingto the planned route is determined to be unable to fulfil the KPI. Theevaluation may more particularly involve an evaluation of theprobability that the cell will be able to provide the required KPI giventhe estimated cell load. In this it may furthermore employ a qualitymodel such as Mean Opinion Score (MOS) or Perceptual Evaluation of VideoQuality (PEVQ). The use of MOS is for instance described in US2014/0032562, which is herein incorporated by reference.

The network condition data analyser 40 then provides the results of theanalysis regarding all the possible next cells, both the cell in thepath and the other possible cells to the to the planned movementadjuster 42, where it is possible that no result is provided in case thenew cell according to the planned router will be able to fulfil the KPI.

The planned movement adjuster 42, then investigates if the next cell inthe planned route fulfils the KPI, and if it does, step 62, then theoriginal route is used without changes, step 60, which may mean that theplanned movement adjuster 42 does nothing in case the UAV controller 30already knows the planned route. Alternatively it may instruct the UAVcontroller 30 to move into the next cell according to the planned route.

However, if the KPI is not fulfilled, step 62, then the planned movementadjuster 42 proposes one or more adjustments, step 64, which proposedadjustments may adjust the planned movement so that the KPI isfulfilled. The proposed adjustment may be a proposal of a new next cell,which may be another neighbour of the current cell, that has the highestprobability of fulfilling the service requirements. In this it ispossible to also weigh the cells based on how big a change of the paththey will involve. A cell involving a smaller change in the path thananother may therefore be selected even though it has a higher load thanthe other candidate. It is here also possible that one or more changesare proposed and if more are proposed they may be provided in an orderaccording to how well they fulfil the KPI. The candidate cells may forinstance be provided in a candidate list, where the cells are providedin the list according to a priority order.

Thereafter the planned movement adjuster 42 investigates a number ofmission constraints. It is possible that the UAV 24 is powered by abattery or by an engine. It is possible that a proposed change will leadto the battery being depleted or the engine running out of fuel beforereaching its destination because of the change to the movement. It isalso possible that the change will introduce physical obstacles in thepath. Another constraint may be so-called geo fencing. Any of theseissues may lead to an inability of the UAV to fulfil the missionconstraints.

If the mission constraint is fulfilled also when there is a change inthe planned movement, then the proposed adjustment is used, step 70,which may involve the planned movement adjuster 42 instruction the UAVcontroller 30 to change UAV settings so that the adjustment isimplemented, which may involve a change in speed, a change in directionas well as a change in both direction and speed. The change in directionmay in this case be a change in horizontal direction, in verticaldirection as well as both in horizontal and vertical direction.

If however, the mission constraint is not fulfilled by any of thecandidate changes, step 66, then the planned movement adjuster mayinstruct the application 26 to lower the KPI, step 68. It may forinstance instruct the application 26 to use a lower bandwidth, which inthe example of video may involve lowering the image resolution.Thereafter the planned movement adjuster 42 instructs the radio networkcondition data analyser 40 to determine new probabilities. The networkcondition data analyser 40 then obtains the new KPI, step 56, and againevaluates the cell loads, however in this case with regard tofulfillment of the new KPI, step 58, whereupon then planned movementadjuster 42 investigates if the new KPI is fulfilled by the originalroute or proposes a change in the movement, which again is compared withthe mission constraint.

This will eventually lead to a movement being selected which bothfulfils the KPI and the mission constraint. It can thereby be seen thatthe adjustment of the planned route may also be based on missionconstraints of the mission in which the application is operated. A KPImay also be changed if none of the movements, changed or unchanged isable to fulfil it.

Finally after the original route has been retained, step 60, or aproposed adjustment selected, step 70, the network condition dataobtainer 34 again obtains radio link quality measures, step 50, whichmay be done when the UAV after having entered a new cell, it again movesto a cell border, which in this case is a cell border of this new cell.

The method may thereafter be repeated in the above-described way untilthe UAV 24 finishes the mission, i.e. reaches its destination.

As the UAV is travelling on its route, the load estimations beingdetermined may be stored and related to the time of day and date of thecollection. The stored data may then be stored in a database of theremote operations centre 22. This data, which is thus statistics of cellload variations of the cells over time, may then be used by the remoteoperations centre 22 when planning a route. If all UAVs associated withthe remote operations centre 22 gathers such historical data within agiven control area of the remote operations centre, i.e. multiple UAVreport measurement data from cells visited in the wireless communicationnetwork, then a database of network quality measures may be built. Asmeasures are aggregated over time, it will be possible to identifyhourly/daily behaviour, which can then be used to optimize performanceof both UAV applications and radio network.

However, it is also possible that such statistics, i.e. statisticaldata, is used during flight. The statistics may for instance be usedwhen the planned movement adjuster 42 of the movement adjusting device32 suggests a change in movement. It is for instance possible to adjustthe speed so that a cell is entered at a time at which it according tothe statistics would not have a high load, which change may involve anincrease of the speed or a lowering of the speed.

As can be seen in the second embodiment, the taking of mission KPIs,practical constraints as above mentioned, etc., into route planning canresult in none/one/several preferred flight paths. In case zero flightpaths are identified, then either it may be necessary to lower missionKPIs, reconsider set mission constraints, or even cancel the missioncompletely. As an alternative one can also consider the case whereseveral UAV missions are uploaded to the remote operations centre 22,and scheduled at appropriate times in order to have all missions meettheir mission KPIs if possible.

As radio network load may vary over e.g. a 24-hour period, abest-before-time for the map that corresponds to estimated route flighttime (and time of the day) may be deduced. If, e.g., specific cells arefound to change from “low loaded” to “highly loaded” during a UAV'sflight time, such cells may be avoided in flight planning. Furthermore,in the event of several planned UAV missions, the scheduling ofindividual UAV missions can also be a dimension added to theoptimization problem.

RSRP and SINR gathered for various cells can also be used to compile aUAV Preferred Cell (UPC) list as input to the planned movement adjuster42. In this case, the wireless transceiver of the UAV may provide radiomeasures to the remote operations centre, which in turn may gather dataand perform analysis of the subsets reflecting UAVs expected missiontimes. Either a regional UPC list can be distributed to all UAVs, or alist per individual UAV.

Taking network load in the context of avoiding cell overloading, a UPClist combined with other mission critical constraints can result inmission plans where a flight route is selected both fulfilling missionconstraints as, e.g., battery time, mission time, etc., but also radionetwork KPIs in the context of avoiding cells identified as high-riskcandidates for having high load during estimated mission time, as wellas not congesting the traffic flow of UAV missions. An example of thisis shown in FIG. 7, which shows a cell map, with a number of cellshaving different cell loads from 0-100%, which cell loads may bestatistical cell loads. In the figure it can also be seen that the UAVis planned to move from point A to point B through a number of cellshaving fairly low cell loads, where the planned route is shown with adashed line.

The mission maps may be planned and provided in the movement adjustingdevice 32. However, since the remote operations centre 22 is not limitedby battery life, memory/storage, processing power, etc., it may bepreferred that mission maps are planned in the remote operations centre22 and sent to the UAVs. If the UAV 24 during its flight from A to Bdetects for example that a specific cell has turned from “low load”(black/dotted) to “high load” (black/dark grey), see FIG. 8, the plannedmovement adjuster 42 may determine alternative routes that circumventthe cell.

In FIG. 8, the dashed line again denotes the planned route of the UAV 24for avoiding statistically known overloaded cells, while the solid linesdenote alternative routes identified by the movement adjustment device32 given the fact that a cell within pre-defined flight route emerged as“too loaded” during operation. It can be seen that two alternativeroutes around the cell having a too high load are suggested for the UAV.

In a further embodiment, the remote operations centre 22 can optimizeits fleet of UAVs with respect to their impact on the wirelesscommunication network; coordinate the total set of flight schedules withrespect to mission task, service and duration, number of UAVs, etc.

It may furthermore be noted that with the addition of UAV missions to aradio network, the height dimension of the radio network may also beutilized in a novel way. The height or z-dimension of the network isknown to differ in terms of radio network characteristics, and suitablezones on the z-dimension can also be taken advantage of, or avoided ifthat is better suited.

The movement adjusting device was above essentially described as beingprovided in the UAV 24. However, it should be realized that it may justas well be provided in the remote operations centre 22. In this case thewireless transceiver 28 of the UAV 24 may be set to send radio linkquality data that it collects to the remote operations centre 22, forinstance via the wireless communication network. The remote operationscentre 22 may then already have knowledge of the service requirement ofthe application. As an alternative it may receive this information fromthe wireless transceiver 28.

The remote operations centre 22 would then estimate cell loads andsuggest possible path changes through evaluating the ability to fulfilthe service requirement given the estimated cell loads and sendsinstructions of path changes to the UAV.

In this regard it should also be realized that the remote operationscentre may in some instances be a part of the wireless communicationnetwork, in which case cell load data reported by the cells may be madeavailable to the remote operations centre. In this case the wirelesstransceiver may thus not need to collect any such data.

It should also be realized that the operation of the movement adjustingdevice may be performed using cloud computing. Servers in a data centremay therefore receive network condition data and application KPIs anddetermine if a change of a route is to be made or not and then send theresults to either the UAV or the remote operations centre 22.

The vessel carrying the wireless transceiver and in which theapplication operated, was above exemplified by a UAV. It should howeverbe realized that the invention is not limited to this type of vessel,but may be used in relation to other types of vessels such as boats,aeroplanes, cars and trucks.

The computer program code of a movement adjusting device may be in theform of computer program product for instance in the form of a datacarrier, such as a CD ROM disc or a memory stick. In this case the datacarrier carries a computer program with the computer program code, whichwill implement the functionality of the above-described movementadjusting device. One such data carrier 72 with computer program code 74is schematically shown in FIG. 9.

The network condition data obtainer of the movement adjusting device maybe considered to form means for obtaining radio network condition dataregarding a group of cells comprising a current cell in which thewireless transceiver is located and a number of neighbouring cells intowhich the wireless transceiver may move. The network condition dataanalyser may in turn be considered to form means for analysing the radionetwork condition data with regard to fulfilling the service requirementof the application. Finally the planned movement adjuster may beconsidered to form means for making an adjustment of the plannedmovement if the analysis indicates that this would improve on thefulfilling of the service requirement.

The means for analysing the radio network condition data may comprisemeans for evaluating cell loads defined in cell load data with regard tofulfilling the service requirement and the means for making anadjustment for the planned movement may comprise means for adjusting theplanned movement so that the cell load along the route after the currentcell is lower after the adjustment than before the adjustment.

The means for obtaining radio network condition data may comprise meansfor determining cell load estimates for the neighbouring cells based onthe radio link quality data and a cell geometry measure, where the cellgeometry measure of a cell is based on a signal strength of the cell asdetected by the wireless transceiver divided by corresponding signalstrengths of the other cells of the group and the cell load estimatesbeing provided as said cell load data

The means for estimating the loads of the neighbouring cells based onresponses to requests for resources sent from the wireless transceiverto the neighbouring cells and for providing the load estimations as thecell load data.

The means for making an adjustment of the planned movement may comprisemeans for changing the cells that the route passes.

The means for making an adjustment of the planned movement mayfurthermore comprise means for basing the adjustment of planned movementon mission constraints of a mission in which the application isoperated.

The means for making an adjustment of the planned movement mayfurthermore comprise means for adjusting the speed with which thewireless transceiver moves for changing the time at which a cell ispassed in the route.

The means for making an adjustment of the planned movement may alsocomprise means for changing the service requirement if it cannot befulfilled with any movement, changed or unchanged.

While the invention has been described in connection with what ispresently considered to be most practical and preferred embodiments, itis to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements. Therefore the invention isonly to be limited by the following claims.

The invention claimed is:
 1. A movement adjusting device for adjusting amovement of a wireless transceiver moving according to a plan along aroute through a wireless communication network while communicating foran application having a service requirement on the wirelesscommunication network, the wireless communication network comprisingcells and the movement adjusting device comprising a processor acting oncomputer instructions wherein said movement adjusting device isoperative to: obtain radio network condition data regarding a group ofcells comprising a current cell in which the wireless transceiver islocated and a plurality of neighboring cells; analyze the obtained radionetwork condition data with regard to fulfilling the service requirementof the application and; while the wireless transceiver is movingaccording to the plan: determine, based on the analysis of the obtainedradio network condition data, whether changing the velocity of thewireless transceiver would improve on the fulfilling of the servicerequirement, and change the velocity of the wireless transceiver as aresult of determining that changing the velocity would improve on thefulfilling of the service requirement.
 2. The movement adjusting deviceof claim 1, wherein the radio network condition data comprises cell loaddata for at least the neighboring cells, the movement adjusting deviceis further configured to evaluate the cell load data, the movementadjusting device is further configured to determine, based on theevaluation of the cell load data, whether changing the velocity of thewireless transceiver would reduce cell load for one or more cells, andthe movement adjusting device is further configured to change thevelocity of the wireless transceiver as a result of determining thatchanging the velocity would reduce the cell load.
 3. The movementadjusting device of claim 2, wherein the radio network condition datacomprises data concerning radio link quality between the cells and thewireless transceiver, the movement adjusting device when obtaining radionetwork condition data is further operative to determine cell loadestimates for the neighboring cells based on the radio link quality dataand a cell geometry measure, the cell geometry measure of a cell beingbased on a signal strength of the cell as detected by the wirelesstransceiver divided by corresponding signal strengths of the other cellsof the group and the cell load estimates being provided as said cellload data.
 4. The movement adjusting device of claim 2, wherein themovement adjusting device when obtaining radio network condition data isfurther operative to estimate the loads of the neighboring cells basedon responses to requests for resources sent from the wirelesstransceiver to the neighboring cells and provide the load estimations assaid cell load data.
 5. The movement adjusting device of claim 1, whenbeing operative to adjust the velocity is operative to change the cellsthat the route passes.
 6. The movement adjusting device of claim 5,wherein the change of cells comprises a change in a vertical direction.7. The movement adjusting device of claim 1, being further operative tobase the adjustment of velocity on mission constraints of a mission inwhich the application is operated.
 8. The movement adjusting device ofclaim 1, wherein the radio network condition data comprises statisticalcell load data.
 9. The movement adjusting device of claim 1, which whenbeing operative to make an adjustment of the velocity is operative toadjust the speed with which the wireless transceiver moves for changingthe time at which a cell is passed in the route.
 10. The movementadjusting device of claim 1, being further operative to change theservice requirement if it cannot be fulfilled with any movement, changedor unchanged.
 11. The movement adjusting device of claim 1, wherein itis provided as a part of a vessel comprising the wireless transceiver.12. The movement adjusting device of claim 1, wherein it is provided asa part of a remote operations centre.
 13. A method of adjusting themovement of a wireless transceiver moving according to a plan along aroute through a wireless communication network while communicating foran application having a service requirement on the wirelesscommunication network, the wireless communication network comprisingcells, the method being performed in a movement adjusting device andcomprising: obtaining radio network condition data regarding a group ofcells comprising a current cell in which the wireless transceiver islocated and a plurality of neighboring cells; analyzing the obtainedradio network condition data with regard to fulfilling the servicerequirement of the application; and while the wireless transceiver ismoving according to the plan: determining, based on the analysis of theobtained radio network condition data, whether changing the velocity ofthe wireless transceiver would improve on the fulfilling of the servicerequirement, and changing the velocity of the wireless transceiver as aresult of determining that changing the velocity would improve on thefulfilling of the service requirement.
 14. The method of claim 13,wherein the radio network condition data comprises cell load data for atleast the neighboring cells, and the method further comprises:evaluating the cell load data, determining, based on the evaluation ofthe cell load data, whether changing the velocity of the wirelesstransceiver would reduce cell load for one or more cells, and changingthe velocity of the wireless transceiver as a result of determining thatchanging the velocity would reduce the cell load.
 15. The method ofclaim 14, wherein the radio network condition data comprises dataconcerning radio link quality between the cells and the wirelesstransceiver, the obtaining of radio network condition data comprisesdetermining cell load estimates for the neighboring cells based on theradio link quality data and a cell geometry measure, the cell geometrymeasure of a cell being based on a signal strength of the cell asdetected by the wireless transceiver divided by corresponding signalstrengths of the other cells of the group and the cell load estimatesbeing provided as said cell load data.
 16. The method of claim 13,wherein the obtaining of radio network condition data comprisesestimating the loads of the neighboring cells based on responses torequests for resources sent from the wireless transceiver to theneighboring cells and providing the load estimations as said cell loaddata.
 17. The method of claim 13, wherein the making of an adjustment ofthe velocity comprises changing the cells that the route passes.
 18. Themethod of claim 13, further comprising basing the adjustment of velocityalso on mission constraints of a mission in which the application isoperated.
 19. The method of claim 13, wherein the radio networkcondition data comprises statistical cell load data.
 20. The method ofclaim 13, wherein the making of an adjustment of the velocity comprisesadjusting the speed with which the wireless transceiver moves forchanging the time at which a cell is passed in the route.
 21. The methodof claim 13, wherein the plurality of neighboring cells comprises afirst neighboring cell and a second neighboring cell, and the radionetwork condition data comprises: i) a first signal strength valueindicating a radio link quality between the first neighboring cell andthe wireless transceiver and ii) second signal strength value indicatingradio link quality between the second neighboring cell and the wirelesstransceiver.
 22. The method of claim 21, further comprising calculatinga first geometry measure for the first neighboring cell, wherein thefirst geometry measure for the first neighboring cell is a function ofthe first and second signal strength values; and calculating a secondgeometry measure for the second neighboring cell, wherein the secondgeometry measure for the second neighboring cell is a function of thefirst and second signal strength values.
 23. The method of claim 22,wherein the plurality of neighboring cells further comprises a thirdneighboring cell, the radio network condition data further comprises athird signal strength value indicating radio link quality between thethird neighboring cell and the wireless transceiver, the first geometrymeasure for the first neighboring cell is a function of the first signalstrength value and the sum of the second and third signal strengthvalues, and the second geometry measure for the second neighboring cellis a function of the second signal strength value and the sum of thefirst and third signal strength values.
 24. The method of claim 23,wherein the first geometry measure for the first neighboring cell is afunction of the first signal strength value divided by a first valuethat is calculated by, at the least, summing the second and third signalstrength values, and the second geometry measure for the secondneighboring cell is a function of the second signal strength valuedivided by a second value that is calculated by, at the least, summingthe first and third signal strength values.